Antenna phase variation correction
A positioning method includes: receiving a positioning signal at a receiver from a positioning satellite; determining an angle of arrival of the positioning signal relative to the receiver; applying a phase correction to the positioning signal, based on the angle of arrival, to produce a phase-corrected signal; and determining a location of the receiver using the phase-corrected signal.
1. A positioning method comprising:
receiving a positioning signal at a mobile device from a positioning satellite;
using an orientation sensor to determine an angle of arrival of the positioning signal relative to the mobile device;
applying, by a processor, a phase correction to the positioning signal, based on the angle of arrival, to produce a phase-corrected signal, the phase correction corresponding to a phase error that the mobile device is configured to introduce to a signal incident upon the mobile device at the angle of arrival; and
determining, by the processor, a location of the mobile device using the phase-corrected signal.
2. The method of claim 1 , wherein applying the phase correction comprises applying a carrier-phase correction to the positioning signal.
3. The method of claim 1 , wherein applying the phase correction comprises applying a code-phase correction to the positioning signal.
4. The method of claim 3 , wherein the phase-corrected signal is a code-phase-corrected signal, the method further comprises applying a carrier-phase correction to the positioning signal to produce a carrier-phase-corrected signal, and wherein determining the location of the mobile device comprises using the code-phase-corrected signal and using the carrier-phase-corrected signal.
5. The method of claim 4 , wherein using the code-phase-corrected signal comprises using the code-phase-corrected signal to determine a coarse location of the mobile device and using the carrier-phase-corrected signal comprises using the carrier-phase-corrected signal to determine a precise location of the mobile device.
6. The method of claim 1 , further comprising retrieving the phase correction for the angle of arrival for the positioning signal from a look-up table stored by the mobile device.
7. The method of claim 1 , wherein determining the angle of arrival of the positioning signal further comprises:
determining an orientation of the mobile device relative to a reference;
determining an estimated location of the mobile device relative to the reference; and
determining a location of the positioning satellite relative to the estimated location of the mobile device.
8. The method of claim 7 , further comprising:
determining the angle of arrival of the positioning signal based on the estimated location of the mobile device and the location of the positioning satellite relative to the estimated location of the mobile device.
9. The method of claim 1 , wherein:
receiving the positioning signal at the mobile device from the positioning satellite comprises receiving a plurality of positioning signals at the mobile device from a corresponding plurality of positioning satellites; and
determining the location of the mobile device using the phase-corrected signal comprises determining the location of the mobile device using a quantity of the plurality of positioning signals, wherein the quantity of the plurality of positioning signals depends upon a position uncertainty of the mobile device.
10. A system comprising:
an antenna configured to receive a positioning signal from a positioning satellite;
an orientation sensor;
a memory; and
a processor communicatively coupled to the antenna and communicatively coupled to, or including, the memory, the processor being configured to:
use the orientation sensor to determine an angle of arrival of the positioning signal relative to the antenna;
apply a phase correction to the positioning signal to produce a phase-corrected signal, the phase correction being based on the angle of arrival, the phase correction corresponding to a phase error that the system is configured to introduce to a signal incident upon the system at the angle of arrival; and
determine a location of the system using the phase-corrected signal.
11. The system of claim 10 , wherein to apply the phase correction the processor is configured to apply a carrier-phase correction to the positioning signal.
12. The system of claim 10 , wherein to apply the phase correction the processor is configured to apply a code-phase correction to the positioning signal.
13. The system of claim 12 , wherein the phase-corrected signal is a code-phase-corrected signal, the processor being further configured to apply a carrier-phase correction to the positioning signal to produce a carrier-phase-corrected signal, and wherein to determine the location of the system the processor is configured to use the code-phase-corrected signal and to use the carrier-phase-corrected signal.
14. The system of claim 13 , wherein the processor is configured to use the code-phase-corrected signal to determine a coarse location of the system and to use the carrier-phase-corrected signal to determine a precise location of the system.
15. The system of claim 10 , wherein the processor is further configured to retrieve the phase correction for the angle of arrival for the positioning signal from a look-up table stored in the memory.
16. The system of claim 10 , wherein the antenna is a patch antenna.
17. The system of claim 16 , wherein the system is a mobile wireless communication device.
18. The system of claim 10 , further comprising an orientation sensor, wherein to determine the angle of arrival of the positioning signal, the processor is further configured to:
determine an orientation of the system relative to a reference;
determine an estimated location of the system relative to the reference; and
determine a location of the positioning satellite relative to the estimated location of the system.
19. The system of claim 10 , wherein to determine the location of the system the processor is configured to determine the location of the system using a plurality of positioning signals, wherein a quantity of the plurality of positioning signals depends upon a position uncertainty of the system.
20. A system comprising:
receiving means for receiving a positioning signal from a positioning satellite;
first determining means, communicatively coupled to the receiving means, for determining an angle of arrival of the positioning signal relative to the receiving means using an orientation sensor;
applying means, communicatively coupled to the first determining means, for applying a phase correction to the positioning signal, based on the angle of arrival, to produce a phase-corrected signal, the phase correction corresponding to a phase error that the system is configured to introduce to a signal incident upon the system at the angle of arrival; and
second determining means, communicatively coupled to the applying means, for determining a location of the system using the phase-corrected signal.
21. The system of claim 20 , wherein the applying means are for applying a carrier-phase correction to the positioning signal.
22. The system of claim 20 , wherein the applying means are for applying a code-phase correction to the positioning signal.
23. The system of claim 22 , wherein the phase-corrected signal is a code-phase-corrected signal, wherein the applying means are first applying means, the system further comprises second applying means for applying a carrier-phase correction to the positioning signal to produce a carrier-phase-corrected signal, and wherein the second determining means are for determining the location of the system by using the code-phase-corrected signal to determine a coarse location of the system, using the coarse location of the system to determine a search window for determining a number of carrier cycles from a satellite to the system, and using the carrier-phase-corrected signal to determine a precise location of the system.
24. The system of claim 20 , wherein for determining the angle of arrival of the positioning signal the first determining means are for:
determining an orientation of the receiving means relative to a reference;
determining an estimated location of the system relative to the reference; and
determining a location of the positioning satellite relative to the estimated location of the system.
25. The system of claim 20 , wherein:
the receiving means are for receiving a plurality of positioning signals from a corresponding plurality of positioning satellites; and
the second determining means are for determining the location of the system using a quantity of the plurality of positioning signals, wherein the quantity of the plurality of positioning signals depends upon a position uncertainty of a mobile device.
26. A non-transitory, processor-readable storage medium storing processor-readable instructions configured to cause a processor to:
determine, for a positioning signal received by an antenna of a device from a positioning satellite, an angle of arrival of the positioning signal relative to the antenna using an orientation sensor;
apply a phase correction to the positioning signal to produce a phase-corrected signal, the phase correction being based on the angle of arrival, the phase correction corresponding to a phase error that the device is configured to introduce to a signal incident upon the device at the angle of arrival; and
determine a location of the device using the phase-corrected signal.
27. The storage medium of claim 26 , wherein to apply the phase correction the instructions are configured to cause the processor to apply a carrier-phase correction to the positioning signal.
28. The storage medium of claim 26 , wherein to apply the phase correction the instructions are configured to cause the processor to apply a code-phase correction to the positioning signal.
29. The storage medium of claim 28 , wherein the phase-corrected signal is a code-phase-corrected signal, the instructions further comprising instructions configured to cause the processor to apply a carrier-phase correction to the positioning signal to produce a carrier-phase-corrected signal, and wherein to determine the location of the device the instructions are configured to cause the processor to:
use the code-phase-corrected signal to determine a coarse location of the device;
use the coarse location of the device to determine a search window for determining a number of carrier cycles from a satellite to the device; and
use the carrier-phase-corrected signal to determine a precise location of the device.
30. The storage medium of claim 26 , wherein to determine the angle of arrival of the positioning signal, the instructions are configured to cause the processor to:
determine an orientation of the device relative to a reference;
determine an estimated location of the device relative to the reference; and
determine a location of the positioning satellite relative to the estimated location of the device.
31. The storage medium of claim 26 , wherein to determine the location of the device the instructions are configured to cause the processor to use a plurality of positioning signals, wherein a quantity of the plurality of positioning signals depends upon a position uncertainty of the device.